The present invention relates to a vibration-damping device for a board for sliding on snow, such as a ski, a monoski, or a snowboard.
It is known that parasitic vibrations of a board for sliding on snow can be damped to improve the comfort of the skier and the grip of the board on hard snow by providing, on the upper surface of the board, at least one stress plate device, namely including a layer of viscoelastic material attached to the upper surface of the board by gluing for example, the upper surface of this viscoelastic material layer itself being joined to a stress plate with a high elasticity modulus. When the board is flexed, a shear is produced between the layer of viscoelastic material located between the upper surface of the ski and the stress plate, which has the effect of damping vibrations. Depending on the type of board considered--ski designed for special slalom or ski designed for giant slalom--the parasitic frequencies to be damped are different, so that the location, size, and number of devices with which the board is equipped are different and matched to each case.
Document WO/01189 describes a ski, which, on its upper surface, has pressure elements disposed in front of and behind the binding area. These elements are made for example of elastic blades each of which is attached by one of its ends to the ski, and rests by the other end on the upper surface of the ski, or on an elastic stop associated therewith.
Document FR-A-2 675 392 relates to a ski having the same characteristics as those described in the foregoing document, with a flexible blade connected to the ski by a rigid link and by a flexible link, said links being spaced lengthwise from one another on the flexible blade.
Document EP-A-0 490 044 relates to a ski having a lower part or base as well as an upper part or stiffener. The link between the stiffener and base is provided by flexible or partially rigid means.
Document FR-A-2 701 215 relates to a ski whose upper surface is equipped with a flexible blade connected to the ski by at least two damping means spaced lengthwise on the ski with respect to each other.
Document FR-A-2 709 974, in the name of the Applicant, relates to a ski equipped with a plate for mounting the binding, said plate having a layer of viscoelastic material surmounted by a stress plate, said plate also having, in its mid-part, an area that is not joined to the ski and is deformed on the side opposite the ski, said plate undergoing, when the ski flexes, buckling between its ends which tend to return the ski to the straight, i.e. non-flexed position.